1. Field of the Invention
The present invention relates to an electric connecter, and more particularly to a RF (radio frequency) microwave connecter for telecommunication.
2. Description of Related Art
Please refer to FIGS. 1A, 1B and 1C. U.S. Pat. No. 6,790,082 discloses a coaxial cable connecter; it allows a hollow portion of an insulator 11 to be coupled to a central terminal; the upper end of the insulator 11 is provided with a groove 111 and a bendable sheet 112 extended upward; the upper end of the central terminal is connected to a first clamping sheet 121 and a second clamping sheet 122. One end of the first clamping sheet 121 is placed in the groove 111 of the insulator 11. One end of the second clamping sheet 122 is connected with one end of the first clamping sheet 121; another end of the second clamping sheet 122 is positioned above the first clamping sheet 121. A metal housing 13 is further allowed to couple to the insulator 11; one side of the metal housing 13 is coupled to a buckling portion 131; the buckling portion 131 is provided with a plurality of pairs of tabs 132, 133, 134 and 135 are respectively extended outward two sides thereof as FIG. 1A shows. An inner wire 21 of a coaxial cable 20 is further allowed to place in the groove 111 and above the first clamping sheet 121, an inner insulator layer 22 of the coaxial cable 20, ground conductor layer 23 and outer insulator layer 24 are respectively positioned at the outside of the groove 111 as FIG. 1B shows. Furthermore, the buckling portion 131 is caused to bend 90 degrees to be leaned against the upper edge of the metal housing 11 to allow the inner conducting wire 21 to be sandwiched between the first clamping sheet 122 and the first clamping sheet 121, the sheet 112 is suppressed at the upper side of the second clamping sheet 122 to enable the second clamping sheet 122 and the buckling portion 131 not to contact with each other. And then, the pairs of tabs 132, 133, 134 and 135 are further bended to cause the tabs 132 and 133 to respectively buckle the metal housing 11 and the tabs 134 and 135 to respectively buckle the ground conductor layer 23 and the outer insulator layer 24 as FIG. 1C shows.
The connecter assembling manner mentioned above allows the coaxial cable 20 to be coupled to the central terminal at the same time that the buckling portion 131 is bended; it is rather time saving for the manufacturing. But, the structure that the first and the second clamping sheets 121 and 122 are disposed on the upper end of the central terminal is rather not easy to be manufactured and rather high for the manufacturing cost. Furthermore, because the first and the second clamping sheets 121 and 122 are made from harder metal, they can rather not clamp the inner conducting wire 21 tightly. When the distance between the first and the second clamping sheets 121 and 122 after being bended cannot match up with the diameter of the inner conducting wire 21, the first and the second clamping sheets 121 and 122 can rather not clamp the inner conducting wire 21 stably; it will influence the signal transmission quality and the coaxial cable in use is rather easy to be loosed if an improper pull force is exerted.
U.S. Pat. No. 7,025,598 discloses a coaxial electric connecter; it provides a coaxial connecter capable of preventing a tongue part of a dielectric from being inclined while being bended and shrinking the height of the tongue part and a cover to attain to the shortness of the connecter. However, the tongue part is not used to match up with a connection part of a central conductor to sandwich an inner conducting wire of a cable. The inner wire is soldered on the connection part of the central conductor. A soldering step is necessary to be added in the manufacturing of the connecter; it rather wastes the labor hour and increases the product cost.
Taiwan Patent No. M307242 and Taiwan Patent N0. M307242 respectively disclose two different RF microwave connecters for telecommunication; they mainly allow the upper end of a central terminal to be provided with a guiding groove and fixing groove; the diameter of the cross section of the guiding groove is larger than the diameter of an inner conducting wire of a coaxial cable, and the diameter of the cross section of the upper end of the fixing groove is smaller than the diameter of the inner conducting wire. Utilizing a particular design that only the inner conducting wire can enter the fixing groove after being thrust allows the inner wire in the fixing groove to be thrust by the wall of the fixing groove to enable the coupling of a central terminal and the inner conducting wire to be more stable and the signal transmission quality to be better. However, a several plate bending steps are necessary to be processed when the central terminal is manufactured, the structures of the guiding groove and the fixing groove can then be formed. As the manufacturing steps is rather complex, it results in the lower production speed and the higher defective rate. Besides, more molds are needed such that the mold fabrication cost is higher.